[shelby1962]

I have a 85 GT with 16" (4 Bolt)rims and would like to upgrade to 17". What width and backspace will fit without any problems? Also what size tires would fit. The car is lowered a bit with Bilstein struts and eibach springs. I would like to run a very low profile tire for some open track events. I now have 245/45 Z rated tires and need bigger rims for some huge brakes.

[EagleAutosports]

Hiya and welcome. Glad you joined us.
You could go up to a 17X8 in the front and 17X9 in the rear with a 245/50 in the front and a 275/50 in the rear with no problems as long as you have 5 1/2-6 inches of backspacing. For the rear you could reverse the quads (if you still have them) and get about another inch of room. For the front with 245 you'll probably have a bit of tire rub when turning right, you could go down to a 235 and be clear. Of course the 50's are the tallest to go with, you obviously can go with a shorter height if you want.

[shelby1962]

Thanks for the input. I'd like to keep front and rear equal for the track. Is there a decent cheap rim on the market seeing that I need two sets for slicks and rain tires?